#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pthread.h>
#include <sched.h>

int ticket = 100;
pthread_mutex_t mutex;
//pthread_cond_t cond = PTHREAD_COND_INITIALIZER;

void *route(void *arg)
{
    char *id = (char *)arg;
    while (1)
    {
        pthread_mutex_lock(&mutex);
        if (ticket > 0)
        {
            usleep(1000);
            printf("%s sells ticket:%d\n", id, ticket);
            ticket--;
            pthread_mutex_unlock(&mutex);
            // sched_yield(); 放弃 CPU
        }
        else
        {
            pthread_mutex_unlock(&mutex);
            break;
            //printf("%s wait on cond!\n", id);
            //pthread_cond_wait(&cond, &mutex);
        }
        //pthread_mutex_unlock(&mutex);

    }
    return nullptr;
}
int main(void)
{
    pthread_t t1, t2, t3, t4;
    pthread_mutex_init(&mutex, NULL);
    pthread_create(&t1, NULL, route, (void*)"thread 1");
    pthread_create(&t2, NULL, route, (void*)"thread 2");
    pthread_create(&t3, NULL, route, (void*)"thread 3");
    pthread_create(&t4, NULL, route, (void*)"thread 4");

    // int cnt = 10;
    // while(true)
    // {
    //     sleep(5);
    //     ticket += cnt;
    //     printf("主线程放票, ticket: %d\n", ticket);
    //     pthread_cond_signal(&cond);
    // }

    pthread_join(t1, NULL);
    pthread_join(t2, NULL);
    pthread_join(t3, NULL);
    pthread_join(t4, NULL);
    pthread_mutex_destroy(&mutex);
}